National Highway Traffic Safety Administration Standard 118 contains regulations to assure safe operation of power operated windows. Standard 118 has been amended to apply to power operated roof panels. It establishes requirements for power window control systems located on the vehicle exterior and for remote control devices. The purpose of the standard is to minimize the risk of personal injury that could result if a limb is caught between a closing power operated window and the window frame. The changes to Standard 118 become effective Sep. 1, 1992. Amended Standard 118 states that the maximum force allowable during an auto closure is to be less than 22 pounds onto a solid cylinder having a diameter of between 4 and 200 millimeters.
Certain problems have been identified with operation of existing power window controls. One problem is an undesirable shutdown of the power window control. It is also desirable to detect a soft obstruction in the window travel path as well as a hard obstruction. The gasket area of the window which avoids water seepage into the vehicle can present a problem to the design of a power window control, since the window or panel encounters different resistance to movement in the gasket region. An additional problem is detection of an obstruction when the motor is first activated.